Hart & Cooley® Return Air Grille, Series: RH45, 12 x 6 in Size, 11-1/2 in Duct Width, 5-1/2 in Duct Height, 7-3/4 in Overall Width, 1 in Overall Depth, Fixed Blade Grate, 110 to 280 cfm Flow Rate, 0.28 sq-ft Effective Area, 45 deg Deflection Angle, 3/4 in Blade Spacing, Aluminum, White Painted, Domestic